SSIS Derived Column IF(IIF)

I use this post as a short reminder for myself, because the Derived Column Transformation Editor in SSIS simply does not spell out how to accomplish this.

The following syntax is used in the Derived Column control to place an IF(IIF) statement :
(Boolean Expression ? True Part : False Part)

So, if I were checking against a Trade Type code column (trade_type_cd) to determine whether this column IS NULL or IS NOT NULL, I could simply write up something like this:
ISNULL(trade_type_cd) ? "<Unknown>" : trade_type_cd